Spool for roll films



March 24, 1936.

SPOOL FOR ROLL FILMS Filed Oct. 16, 1933 INVENTOR.

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' ATTORNEYS.

H. HENKELS 2,035,158

Patented Mar. 24, 1936 PATENT OFFICE SPOOL FOR ROLL FILMS Hugo Henkels, Wuppertal-Elberfeld, Germany Application October 16, 1933, Serial No. 693,852

In Germany May 19, 1933 1 3 Claims. (01. 242-71) This application has been filed in Germany on May 19, 1933.

The present invention relates to spools for roll films for photographic cameras of the kind consisting of a sheet iron tube and two sheet iron end discs fixed to the end of the tube. In spools of this kind one of the end discs is, as a rule, provided with a circular hole for engagement with the pivot pin of the spool, whilst the other end disc is usually provided with a slot extending in the direction of the diameter of the disc. This slot serves for engagement with a second pivot pin, which latter is usually constituted by a key formed with a. double key-bit or ward and serving for rotating the spool. In order to provide at the edges of the slot stop and guide surfaces for the key-bit of the driving key, it is usual to bend the edges of the slot at an angle towards the inner side of the end disc. As, however, the width of the bent edge portions is very limited owing to the small width of the slot, the stop surfaces have only a very small dimension in the axial direction of the spool. The carrier key which serves for rotating the spool is not, as a rule, provided with a wide bit or ward. Particularly in connection with cheap cameras, the bit or ward of the key is mostly constituted by a thin pin or piece of wire passed through a cross bore in the end of the key stem. Consequently, the stop and guide surfaces constituted by the bent-over slot edge portions of the key slot of the end disc, do not provide very satisfactory means for the guidance and engagement of the driving key. The result is that the key-bit or ward is frequently pushed too far into the slot of the end disc, so that the key-bit is located in rear of the stop surfaces and is incapable of carrying the spool on rotation of the key.

The object of the invention is to provide a film spool in which the drawbacks of the known spools are avoided by substituting for the known key slot in the end disc, a boss integral with and drawn from the material of the end disc, said boss being of elongated shape and formed with a bottom or base provided with a hole through which the stem of the key passes. Owing to the fact that the boss is drawn from the material of the end disc, the depth of the boss in the axial direction can be made of sufficient size to provide even in the case of carrier keys having a simple bit consisting of a pin or piece of wire, satisfactory stop and guide surfaces, whereby a perfectly reliable rotation of the spool by the key is insured. The bottom or base of the boss serves at the same time as a stop limiting the depth of the insertion of the key. It is, therefore, impossible for the key, on being inserted into the 'spool of the camera, to be" pushed too far and the bit of the key cannot be moved past the stop and bearing surfacesof the boss. 5

Finally, the central hole provided in the bottom or base of the boss provides a very satisfactory central guide for the stem, so that the spool will always be exactly centered at both ends.

The accompanying drawing illustrates by way of example one construction embodying the features of the invention.

Fig. 1 is a sectional elevation of an improved film spool,

Fig. 2 is a perspective inner view of the left hand end disc, and

Fig. 3 is an outer end view of the same end disc.

Referring to the drawing a designates the main body of the spool made in the usual manner from a strip of sheet iron. 15 and b are the two end discs or spool flanges which are fixed to the ends of the tube a in any known or suitable manner, for instance, by bending the tube ends 1 into folded portions of the end discs.

The right hand end disc b of the spool is formed in its centre with a circular hole 0 for the engagement of the usual stationary pivot pin of the spool provided in the camera. The edge portion of the central hole is, as shown in the drawing, expanded or drawn to form a guide or 30.

bearing hub. The left hand end disc 12 is formed in its centre with a boss 11 for the engagement of the usual carrier key provided in the camera by means of which the spool may be rotated. This key consists, as usual, of a stem portion which serves at the same time as the second pivot pin of the spool, and a double ward or key-bit. The double key-bit or ward is mostly constituted by a cross pin or cross wire passed through a cross bore of the stem of the key. The boss is elongated and is produced by drawing from the material of the middle portion of the disc. The major axis of the boss extends in the direction of the diameter of the end disc W. The boss at is comparatively narrow at its ends and has a central portion of a larger diameter. The bottom or base of the boss is provided with a central or circular hole 0 through which the end of the stem of the key is passed. The boss is therefore closed on all sides except the side forming the insertion opening for the key and. the central hole at the opposite side. It will be seen that the walls of the drawn boss provide very wide and satisfactory bearing and guide surfaces for the ward or pin of the carrier key, whereby efiicient and satisfactory rotation of the spool by means of the key is insured. The bottom of the boss constitutes an axial stop for the key Ward so that the latter cannot be pushed past the bearing surfaces. The central hole in the bottom of the boss also constitutes a very satisfactory guide for centering the stem of the key.

I claim:

1. A spool for roll films consisting of a tubular main body and two end discs rigidly connected with said tubular main body, one of said end discs having an integral inwardly extending elongated hollow boss for the reception of a driving key provided with a bit or ward, said boss comprising lateral walls for guiding and engaging with the whole of the key including the stem and bit thereof, and a bottom portion formed with a central opening for the reception of the end of the key stem and constituting a stop for the bit of the key.

2.'A spool for roll films consisting of a tubular main body and two end discs rigidly connected with said tubular main body, one of said end discs having an integral inwardly extending elongated hollow boss drawn from the middle portion of the disc for the reception of a driving key provided with a bit or ward, said boss comprising lateral walls for guiding and engaging with the whole of the key including the stem and bit thereof, and a bottom portion formed with a central opening for the reception of the end of the key stem and constituting a stop for the bit of the key.

3. A spool for roll films comprising in combination: a tubular main body made of sheet iron; two end discs rigidly attached to the ends of said tubular body and made of sheet iron, one of said discs having an integral hollow central elongated boss drawn inwards from the centre portion of said disc to a considerable extent, said boss comprising a central middle portion of cylindrical shape having two portions extending diametrically from it, said last named portionsbeing of less width than the diameter of said middle portion, and a bottom portion provided with a central hole, whereby said boss is adapted for the reception and guidance by said middle and diametrically extending portions, of a driving key provided with a bit or ward, whilst the bottom portion is adapted for the reception of the stem of the key only and forms a stop for the bits of the key, substantially as described.

HUGO HENKELS. 

